The invention relates to a process for preparing normally liquid hydrocarbonaceous products from a hydrocarbon feed containing linear- and branched olefins.
A variety of one--and multistep--processes is known for the preparation of hydrocarbonaceous products such as oxygenates, middle distillates, alkylates and gasoline from an olefinic feed containing e.g. propene and/or butenes. These known processes have a number of draw-backs, however. One-step processes don't provide the flexibility to prepare a number of different products starting from a multi-component feed, whereas multi-step processes in many cases require splitting-up of such a feed in order to convert each component under optimal conditions.
In particular with the oligomerization of olefinic feed mixtures in the presence of solid catalysts it has been observed that the quality of the liquid hydrocarbon products (e.g. the cetane number of the gas oil fraction) is lower than when an olefinic feed substantially comprising linear olefins is processed.
Surprisingly, it has now been found that by first selectively converting branched olefins present in a feed mixture, followed by product separation and oligomerization of the linear olefins, excellent liquid hydrocarbon oligomerization products can be obtained in addition to valuable conversion products from the branched olefins.